In this Monday, April 6, 2015 photo, two-year-old Oratilwe Hlongwane, also known as DJ AJ to his fans, removes his headphones after playing with the buttons and knobs of a sophisticated music system in control of the beat of the bass-heavy house music at his Alexandra home in Johannesburg. The toddler is already able to select and play music from a laptop and has become a viral phenomenon on South Africa's social media.

Teenage listeners tend to tune in nearly exclusively to popular music and proceed to listen to steadily less popular music as they approach their 20s. This makes sense as many kids start their musical education with top 40 songs and branch out as their tastes develop. By their early 30s, most people listen to music that either never was mainstream or has fallen in popularity since they first heard it.

“First, listeners discover less-familiar music genres that they didn’t hear on FM radio as early teens, from artists with a lower popularity rank,” Ajay Kalia, the study's author, wrote in a blog post. “Second, listeners are returning to the music that was popular when they were coming of age — but which has since phased out of popularity.”

Dividing the data by gender, Kalia found that males age out of popular music faster than women, and at all ages women listen to more popular music than men do – although this could be due to the increasing prominence of women on the Billboard Top 100 list.

Having children also affects one’s musical taste. At all ages, parents listen to less popular music. Kalia explained that “becoming a parent has an equivalent impact on your ‘music relevancy’ as aging about 4 years.” Additionally, the gender gap is not as wide among parents.

These trends are all fairly intuitive, but while people tend to stop keeping up with new music, the same doesn't generally happen with movies or books.

“I see so many people my age sticking with the music they liked in high school and college,” music critic Steven Hyden, said. “Which, again, I find weird because it’s not like these people are also content to just re-watch 'Pulp Fiction' and 'Happy Gilmore,' or re-read 'The Catcher in the Rye.' This arrested development is specific to music.”

This questions has endless answers, which will likely vary from person to person, but music critic Noel Murray suggests it could be because of the cultural role each medium plays.

“Current movies and current television are frequently more a part of the cultural conversation than current music – or at least good current music,” Murray said. “It feels more essential in some ways to keep up with movies, TV, and books.”

On the other hand, Hyden argues that nothing really lives up to discovering your favorite bands for the first time. Whereas a story in a film, TV show, or novel – regardless of how moving it may be – is probably not going to prevent you from wanting to hear other stories.